JP2004280079A - Picture display device and portable terminal device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a picture display device whose brightness is not lowered on reflection display and which has excellent display quality, and to provide a portable terminal using the same. <P>SOLUTION: A plurality of display units including a pixel for displaying a picture for a left eye and a pixel for displaying a picture for a right eye in one display unit are arranged in a matrix state on a display panel 2. A lenticular lens 3 is arranged in front of the display panel 2, is constituted so that projecting shape is repeatedly formed on its surface and distributes light emitted from the respective pixels in a right-and-left direction linking the pixel for displaying the picture for the left eye and the pixel for displaying the picture for the right eye in the display unit. A reflector 4 reflects external light toward the display panel, and rugged shape 41 is formed on the surface of the reflector. Then, the focal distance (f) of the lens is different from a distance HR between the surface of the reflector 4 and the top of the lens. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image display device using a lens such as a lenticular lens or a fly-eye lens and capable of displaying mutually different images toward a plurality of viewpoints, and a portable terminal device using the same. The present invention relates to an image display device with excellent display quality without a decrease in brightness and a portable terminal device using the same.

  Conventionally, a display device capable of displaying a stereoscopic image has been studied. In 280 BC, the Greek mathematician Euclid considered that "stereoscopic vision is the sensation that can be obtained by the left and right eyes simultaneously viewing separate images of the same object viewed from different directions." Non-Patent Document 1: Chihiro Masuda, "3D Display" Sangyo Tosho Co., Ltd.) That is, as a function of the stereoscopic image display device, it is necessary to present images with parallax to both the left and right eyes.

  As a method for specifically realizing this function, a number of stereoscopic image display methods have been studied. Conventionally, these methods can be roughly classified into a method using glasses and a method not using glasses. Among these, the method of using glasses includes an anaglyph method using a difference in color, a polarizing glasses method using polarized light, and the like, but since it is essentially impossible to avoid the burden of wearing glasses, in recent years, A spectacle-free system that does not use spectacles has been actively studied.

  Examples of the method without glasses include a lenticular lens method and a parallax barrier method. The lenticular lens system is said to have been invented around 1910 by Ives et al. The parallax barrier method was conceived by Berthier in 1896 and was proven by Ives in 1903.

  The lenticular lens system was invented around 1910 by Ives et al., As described in Non-Patent Document 1, for example. FIG. 22 is a perspective view showing the lenticular lens 121, and FIG. 23 is an optical model diagram showing a stereoscopic display method using the lenticular lens. As shown in FIG. 22, one surface of the lenticular lens 121 is flat, and a convex portion (cylindrical lens) 122 extending in one direction is formed on the other surface, and the longitudinal directions thereof are parallel to each other. Are formed.

  Then, as shown in FIG. 23, a lenticular lens 121, a display panel 106, and a light source 108 are arranged in this order from the observer side, and a pixel of the display panel 106 is located on a focal plane of the lenticular lens 121. In the display panel 106, pixels 123 that display an image for the right eye 141 and pixels 124 that display an image for the left eye 142 are alternately arranged. At this time, a group consisting of the pixel 123 and the pixel 124 adjacent to each other corresponds to each convex portion 122 of the lenticular lens 121. As a result, the light emitted from the light source 108 and transmitted through each pixel is distributed by the convex portion 122 of the lenticular lens 121 in the direction toward the left and right eyes. This makes it possible for the left and right eyes to recognize mutually different images, and for the observer to recognize a stereoscopic image.

  On the other hand, the parallax barrier method was conceived by Berthier in 1896 and was demonstrated by Ives in 1903. FIG. 24 is an optical model diagram showing a stereoscopic image display method using a parallax barrier. As shown in FIG. 24, the parallax barrier 105 is a barrier (light-shielding plate) in which a number of thin vertical stripe openings, that is, slits 105a are formed. A display panel 106 is arranged near one surface of the parallax barrier 105. In the display panel 106, pixels 123 for the right eye and pixels 124 for the left eye are arranged in a direction orthogonal to the longitudinal direction of the slit. A light source 108 is arranged near the other surface of the parallax barrier 105, that is, on the opposite side of the display panel 106.

  Light emitted from the light source 108, passing through the opening (slit 105a) of the parallax barrier 105, and transmitting through the right-eye pixel 123 becomes a light beam 181. Similarly, light emitted from the light source 108, passing through the slit 105a, and passing through the left-eye pixel 124 becomes a light flux 182. At this time, the position of the observer at which the stereoscopic image can be recognized is determined by the positional relationship between the parallax barrier 105 and the pixel. That is, the observer's right eye 141 is within the passband of all the light fluxes 181 corresponding to the plurality of right-eye pixels 123, and the observer's left eye 142 is within the passband of all light fluxes 182. Is required. This is the case where the midpoint 143 between the observer's right eye 141 and left eye 142 in FIG. 24 is located within the rectangular three-dimensional visible area 107 shown in FIG. Of the line segments extending in the arrangement direction of the right-eye pixels 123 and the left-eye pixels 124 in the three-dimensional visible region 107, the line segment passing through the intersection 107a of the diagonal line in the three-dimensional visible region 107 is the longest line segment. For this reason, when the middle point 143 is located at the intersection 107a, the tolerance in the case where the position of the observer is shifted in the left-right direction is maximized. Therefore, in this stereoscopic image display method, the distance between the intersection 107a and the display panel 106 is set as the optimum observation distance OD, and it is recommended to the observer to observe at this distance. Note that a virtual plane in which the distance from the display panel 106 in the three-dimensional visible range 107 is the optimum viewing distance OD is referred to as an optimum viewing plane 107b. Accordingly, the light from the right-eye pixel 123 and the left-eye pixel 124 reaches the right eye 141 and the left eye 142 of the observer, respectively. For this reason, the observer can recognize the image displayed on the display panel 106 as a stereoscopic image.

  When the parallax barrier method was initially conceived, the parallax barrier was disposed between the pixel and the eye, and thus was problematic in that it was obstructive and low in visibility. However, with the recent realization of the liquid crystal display device, the parallax barrier 105 can be arranged on the back side of the display panel 106 as shown in FIG. For this reason, a parallax barrier type stereoscopic image display device is currently being actively studied.

  However, while the parallax barrier method is a method of “hiding” unnecessary light beams by a barrier, the lenticular lens method is a method of changing the traveling direction of light, and the lenticular lens method is, in principle, the brightness of the display screen There is an advantage that there is no decrease. Therefore, application to portable devices and the like, in which high luminance display and low power consumption performance are particularly important, is being studied. A conventional stereoscopic image display device using a lenticular lens uses a transmission type liquid crystal display device as a display panel.

  As an image display device using a lenticular lens, in addition to a stereoscopic image display device, a multiple image simultaneous display device that simultaneously displays a plurality of images has been developed (for example, see Patent Document 1). This is a display that simultaneously displays different images for each observation direction under the same conditions using an image distribution function of a lenticular lens. Thereby, one multiple image simultaneous display device can simultaneously provide mutually different images to a plurality of observers located in mutually different directions with respect to this display device. Patent Literature 1 states that by using this multiple image simultaneous display device, the installation space and electricity cost can be reduced as compared with a case where a normal single image display device is prepared for the number of images to be simultaneously displayed. Have been.

  In addition, conventionally, use of a reflective flat panel image display device having a reflector for a display panel has been studied. In a reflective display device, light incident from the outside is reflected by a reflective plate located inside the display device, and the reflected light is used as a display light source. Therefore, a backlight or a sidelight as a light source is not required. On the other hand, a transmissive display device requires a light source such as a backlight or a sidelight. Therefore, when a reflective display device is used for a display panel, lower power consumption can be achieved than when a transmissive display device is used. For this reason, in recent years, the application of a reflective display device to a portable device or the like has been promoted.

  However, when a reflective display device is used as described above, when the shape of the reflector is a flat surface, external light is reflected like a mirror surface, so that the pattern of a light source such as a fluorescent lamp is reflected. However, there is a problem that display quality is deteriorated. In addition, since only the incident light from a certain specific angle contributes to the display for the observer, there is a problem that the efficiency of using external light is reduced.

  For this reason, as described in Japanese Patent Application Laid-Open No. H8-184846 (Patent Document 2), a technique of providing a reflection plate with an uneven shape has been proposed. FIG. 25 shows an example of the structure of a reflector having an uneven shape. An organic film is provided below the reflecting plate 4, and the unevenness 41 is formed on the surface of the reflecting plate 4 by forming irregularities on the surface of the organic film. Due to this uneven shape, external light incident from a specific direction is diffused and reflected in various directions. External light incident from various directions is also reflected toward the observer. As a result, reflection of the light source pattern can be prevented, and external light having various angles can be used for display.

  As described above, the three-dimensional image display device using the lenticular lens and the reflection type flat display device are each known per se.

Chihiro Masuda "3D Display" Sangyo Tosho Co., Ltd. JP 06-332354 A (FIG. 9) JP-A-8-184846

  However, although a stereoscopic image display device using these lenticular lenses and a reflective flat display device both have the advantage of low power consumption, a stereoscopic image display device combining the two has conventionally existed. Did not.

  Therefore, the present inventors have eagerly aimed at realizing a display device capable of displaying a stereoscopic image in reflective display by combining the above-described stereoscopic image display device and a reflective flat display device, and reducing power consumption. investigated. As a result, the following new problems became apparent.

  That is, there is a problem that in a stereoscopic visible region that should have substantially uniform luminance, an area where luminance is partially reduced occurs depending on an observation position. When the observation position is changed, the display appears dark at a position where the luminance is reduced, and in some cases, a dark line pattern is observed. In addition, the quality of the stereoscopic image display deteriorates due to the uneven brightness.

  Before describing this problem, first, a stereoscopic image display device using a conventional transmissive liquid crystal display panel and a lenticular lens will be described. FIG. 26 is a perspective view showing a binocular stereoscopic image display device. One cylindrical lens constituting the lenticular lens 3 is arranged corresponding to two pixels (a left-eye pixel 51 and a right-eye pixel 52) of the display panel 2. As shown in FIG. 27, light from the left-eye pixel 51 or the right-eye pixel 52 of the display element is refracted by the lenticular lens 3 and emitted toward the region EL or ER, respectively. For this reason, the observer positions the left eye 61 in the area EL and the right eye 62 in the area ER, so that the image for the left eye is input to the left eye 61 and the right eye 62 is input to the right eye 62. Is input, and a stereoscopic image can be recognized.

Next, the size of each part of the stereoscopic image display device using the lenticular lens will be described using an optical model shown in FIG. The distance between the center of the convex portion on the surface of the lenticular lens 3 and the display pixel is H, and the refractive index of the lenticular lens 3 is n. Note that the center of the convex portion on the surface of the lenticular lens 3 is the vertex of the lenticular lens 3. It is assumed that one surface of the lenticular lens 3 is a flat surface, and a large number of convex cylindrical lenses, that is, a large number of convex portions 31 extending in one direction are arranged on the other surface. The focal length of the lenticular lens 3 is f, and the lens pitch is L. The pixels of the display element 2 each include one pixel 51 for the left eye and one pixel 52 for the right eye. The pitch of each pixel is P. One set of two pixels, one left-eye pixel 51 and one right-eye pixel 52, corresponds to one protrusion 31. The distance between the lenticular lens 3 and the observer is defined as OD, and the enlarged projection width of the pixel at this distance OD, that is, the left-eye pixel 51 and the right pixel 51 on the virtual plane parallel to the lens and separated from the lens by the distance OD. Let the width of the projected image of the eye pixel 52 be e. Furthermore, the wrench from the center of the convex portion 31 located in the center of the lenticular lens 3, wrench the distance to the center of the convex portion 31 located at the end of the lenticular lens 3 and W _L, the pixel for the left eye in the center of the display element 2 51 and the center of the pair of right-eye pixel 52, the distance between the center of the pixel pair located at the end of the display element 2 and W _P. Furthermore, the incident angle and the outgoing angle of the light at the convex portion 31 located at the center of the lenticular lens 3 are α and β, respectively, and the incident angle and the outgoing angle of the light at the convex portion 31 located at the end of the lenticular lens 3 are respectively. Let γ and δ. Distance W the difference between _L and the distance W _P is C, the distance W number of pixels contained in the area of _P is referred to as the 2m.

  Usually, a lenticular lens is often designed according to a display element, so P is treated as a constant. Further, n is determined by selecting the material of the lenticular lens. On the other hand, the pixel expansion projection width e at the distance OD between the lens and the observer and the observation distance OD is set to a desired value. Using these values, the distance H between the lens surface and the pixel and the lens pitch L are determined. From Snell's law and the geometric relationship, the following equations 1 to 6 hold. In addition, the following equations 7 to 9 hold.

  From the above equations 2, 1 and 3, the following equations 10, 11 and 12 respectively hold.

  Further, the following Expression 13 is established from Expressions 6 and 9. Also, from the above equations 7 to 9, the following equation 14 is established. Further, the following equation 15 is established from the above equation 5.

  As shown in the following equation (16), the distance H between the pixel and the center of the convex portion on the surface of the lenticular lens is usually set to be equal to the focal length f, so that the radius of curvature r of the lens is obtained by the following equation (17).

  Next, based on the above design, computer simulation of the stereoscopic image display device was performed using a commercially available ray tracing simulator. FIG. 29 is a diagram showing an optical model used for this simulation. In this example, a display element having a pixel pitch P of 0.24 mm is assumed, and polymethyl methacrylate (PMMA) having a refractive index n of 1.49 is used as the material of the lenticular lens 3, and the lens and the viewer When the distance OD is set to 280 mm, the pixel enlarged projection width e at the distance OD is set to 65 mm, and the value of m is set to 60, the distance H between the lens surface and the pixel is 1.57 mm and the focal length f of the lens is Is 1.57 mm, the lens pitch L is 0.4782 mm, and the radius of curvature r of the lens is 0.5161 mm. As a result, the light receiving surface 18 is located at a position 280 mm from the lens surface. In addition, since the pixel pitch P is 0.24 mm, the width of the pixel is 0.24 mm. Then, the light emitting region 17 was arranged at the center of the pixel. The width of the light emitting region 17 was set to 0.186 mm. Therefore, non-display areas each having a width of 0.027 mm are provided on both sides of the light emitting area 17. The light emitted from the light emitting region 17 was diffused light. The non-display area corresponds to a light-shielding portion arranged for the purpose of preventing color mixture of the display device or transmitting a display signal to a pixel. Furthermore, in order to facilitate the simulation, only one pixel for the right eye located near the center of the display element was set.

  FIG. 30 is a graph showing the results of this simulation, in which the horizontal axis represents the observation position on the observation surface separated by a distance OD = 280 mm from the lens surface, and the vertical axis represents the illuminance at this observation position. The illuminance in the range of −60 mm to 0 mm at the observation position on the horizontal axis is high, and the value is substantially uniform. That is, when the right eye is arranged in this range, a sufficient amount of light is incident on the right eye and almost no light is incident on the left eye. This is because, in an actual stereoscopic image display device, when a left-eye image is displayed on a left-eye pixel and a right-eye image is displayed on a right-eye pixel, a left-eye image is input to the left eye. The right-eye image is input to the right eye, and the separation between the two images is sufficiently ensured. As a result, this means that the observer can recognize the stereoscopic image well.

  Next, in order to make the above-mentioned three-dimensional display device a reflection type display, a computer simulation was performed by setting a light emitting area of a pixel to a reflection plate. FIG. 31 is a diagram showing an optical model used for this simulation. The concavo-convex shape 41 is set only on a part of the reflection plate 4 in order to clarify the difference from the flat portion. Specifically, three rows of projections having a slope angle of 30 ° and a height of 2 μm were provided at a pitch of 10 μm with respect to the center of the reflector. The light source 19 was set to have a lateral width covering all the lenses, and was disposed at a position 1 mm from the lens surface. The light from the light source 19 is diffused light. FIG. 32 is a graph showing the results of this simulation. It can be seen that the illuminance is reduced at the position of −30 mm. That is, when observed at this position, there is a problem that the display becomes dark and observed.

  Further, in the above simulation, one pixel is taken up. However, in general, the uneven shape exists at random positions over all display pixels. Then, since the brightness is observed differently for each pixel of the display device, the difference in brightness is observed while being superimposed on the stereoscopic image. As a result, there is a problem that the quality of the stereoscopic image display is reduced. Note that such a problem is not limited to the stereoscopic image display device and generally occurs in a display device that simultaneously displays different images from a plurality of viewpoints, such as the above-described multiple image simultaneous display device. I do.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an image display device that does not decrease in brightness in reflective display and has excellent display quality, and a portable terminal using the same.

  In the image display device according to the first aspect of the present invention, a plurality of display units including at least a pixel for displaying an image for a first viewpoint and a pixel for displaying an image for a second viewpoint in one display unit are arranged in a matrix. A display panel, a lens provided with a plurality of lens elements disposed in front of the display panel and configured to refract light emitted from the pixels and emit light in different directions from each other; A reflector that is disposed behind the panel and reflects external light toward the lens and has an uneven shape on the surface, and the focal length f of the lens is between the surface of the reflector and the vertex of the lens. The distance H is different from the distance H.

  In the present invention, since the light condensed by the lens has a certain area on the surface of the reflector, the light is reflected at a plurality of types of inclination angles, such as an uneven slope and a flat portion, and the reflected light is Proceed to various angles. Since this part also advances toward the observer, it can contribute to display. Thereby, it is possible to prevent a decrease in luminance due to the uneven shape.

  An image display device according to a second aspect of the present invention includes a pixel that includes a transmission area and a reflection area in one display unit and displays an image for a first viewpoint, and a pixel that includes a transmission area and a reflection area and displays an image for a second viewpoint. And a plurality of lens elements disposed in front of the display panel and refracting light emitted from each of the pixels and emitting the light in mutually different directions. And a light source that irradiates light to the transmissive area of the display panel, and reflects external light toward the lens disposed in a reflective area in the display panel or behind a reflective area of the display panel. And a reflector having an uneven shape on the surface, wherein the focal length f of the lens is different from the distance H between the surface of the reflector and the vertex of the lens.

  Also in this image display device, in the reflection area, since the light condensed by the lens has a certain area, the light is reflected at a plurality of types of inclination angles, such as an uneven slope and a flat portion, and the reflected light is Proceed to various angles. Since this part also advances toward the observer, it can contribute to the display, thereby preventing a decrease in luminance due to the uneven shape.

  In the image display device according to the present invention, it is preferable that a focal length of the lens is smaller than a distance between the reflector and the lens.

  Further, the image display device according to the present invention, when the pitch of the lens is L and the minimum pitch of the uneven shape is V, the focal length f of the lens, and the distance between the surface of the reflector and the vertex of the lens. It is preferable that the distance H satisfies Expression 18.

  Further, the image display device according to the present invention, the optimal observation distance is OD, the enlarged projection width of the pixel at the optimal observation distance OD is e, the refractive index of the lens is n, the pixel pitch of the display element is P. In this case, it is preferable that the focal length f of the lens satisfies Expressions 19 to 21 below.

  Thereby, in the present invention, it is possible to further suppress the decrease in luminance due to the uneven shape.

  The image display device according to the present invention includes the optimal observation distance OD, the pixel enlarged projection width e, the refractive index n of the lens, the distance H between the surface of the reflector and the center of the convex portion of the lens surface, and It is preferable that the pixel pitch P of the display element satisfies Expressions 19 to 20 and Expression 22 below.

  The present invention can be applied to a case where the distance between the lens surface and the pixel is fixed, and can suppress a decrease in luminance due to the uneven shape.

  The image display device according to the present invention can be configured such that the focal length of the lens is larger than the distance H between the surface of the reflector and the vertex of the lens.

  Further, in the image display device according to the present invention, the focal length f of the lens, the distance H between the surface of the reflector and the vertex of the lens, the lens pitch L, and the minimum pitch V of the concave and convex shape are as follows. Equation 23 is preferably satisfied.

  Further, in the image display device according to the present invention, the optimum observation distance OD, the pixel enlarged projection width e, the refractive index n of the lens, the focal length f of the lens, and the pixel pitch P of the display element are expressed by the above-mentioned equations (19) to (19). 21 is preferably satisfied. In the present invention, the distance between the lens surface and the pixel can be reduced. Thereby, the total thickness of the image display device can be reduced.

  Further, the image display device according to the present invention is characterized in that the optimum observation distance OD, the pixel enlarged projection width e, the refractive index n of the lens, the distance H between the surface of the reflector and the vertex of the lens, and the display It is preferable that the pixel pitch P of the element satisfies the expressions 19 to 20 and 22. In the present invention, the focal length can be set large. As a result, the height of the lens irregularities can be reduced, so that the lens pattern becomes less noticeable, and the image display quality is improved.

  In the image display device according to the third aspect of the present invention, a plurality of display units including at least a pixel for displaying an image for a first viewpoint and a pixel for displaying an image for a second viewpoint are arranged in a matrix. A display panel, a lens provided with a plurality of lens elements disposed in front of the display panel and configured to refract light emitted from the pixels and emit light in different directions from each other; A reflector that is disposed behind the panel and reflects external light toward the lens and has an uneven shape on the surface, and the unevenness on the surface of the reflector reflects light that is incident multiple times. It is characterized by having a shape.

  An image display device according to a fourth aspect of the present invention includes a pixel that includes a transmission area and a reflection area in one display unit and displays an image for a first viewpoint, and a pixel that includes a transmission area and a reflection area and displays an image for a second viewpoint. A display panel in which a plurality of display units are arranged in a matrix, and a plurality of lens elements disposed in front of the display panel and refracting light emitted from each of the pixels and emitting light in different directions from each other. A formed lens, a light source that irradiates light to the transmission area of the display panel, and a reflection area in the display panel or a reflection area of the display panel that is disposed behind the reflection area and reflects external light toward the lens. And a reflector having an uneven shape on the surface thereof, wherein the uneven shape on the surface of the reflector has a shape that reflects incident light a plurality of times.

  In the present invention, a part of the light reflected on one slope of the uneven shape can travel in the direction of the observer after being re-reflected on another slope. Thereby, it is possible to prevent a decrease in luminance due to the uneven shape.

  Furthermore, in the image display device according to the present invention, it is preferable that the inclination angle of the uneven shape is 50 ° or more. Thereby, it is possible to further suppress a decrease in luminance due to the uneven shape.

  In the image display device according to the fifth aspect of the present invention, a plurality of display units including at least a pixel displaying an image for a first viewpoint and a pixel displaying an image for a second viewpoint are arranged in a matrix in one display unit. A lenticular lens formed with a plurality of cylindrical lenses that are arranged in front of the display panel, refract light emitted from the pixels and emit light in different directions from each other, and the display panel or A reflector disposed behind the display panel to reflect external light toward the lens and having a concave and convex shape on the surface, and a slope having a certain inclination angle in the concave and convex shape in the arrangement direction of the cylindrical lenses. Are characterized in that the existence probabilities are uniform in the pixel.

  An image display device according to a sixth aspect of the present invention includes a pixel that includes a transmission area and a reflection area in one display unit and displays an image for a first viewpoint, and a pixel that includes a transmission area and a reflection area and displays an image for a second viewpoint. A display panel in which a plurality of display units are arranged in a matrix, and a plurality of cylindrical lenses arranged in front of the display panel and refracting light emitted from each of the pixels and emitting light in different directions. A lenticular lens formed, a light source for irradiating light to the transmission area of the display panel, and a reflection area in the display panel or a reflection area of the display panel disposed behind the reflection area to reflect external light toward the lens. And a reflector having an uneven shape on the surface, and in the arrangement direction of the cylindrical lenses, there is a slope having a certain inclination angle in the uneven shape. Probability characterized in that it is uniform in the pixels.

  Since the cylindrical lens has no lens effect in the longitudinal direction, the optical effect of the concavo-convex shape in each pixel is obtained by integrating the effect in the longitudinal direction of the cylindrical lens. Therefore, assuming that the existence probability of a slope having a certain inclination angle in the concavo-convex shape is uniform in the pixel, the optical characteristics are such that the same inclination angle is continuously arranged at all positions in the arrangement direction of the cylindrical lenses. It is equivalent to the case. As a result, it is possible to prevent a decrease in luminance due to the uneven shape.

  Further, in the image display device according to the present invention, it is preferable that a pitch of the concave and convex shapes in a longitudinal direction of the cylindrical lens is smaller than a pitch of the concave and convex shapes in an arrangement direction of the cylindrical lenses. Thereby, the uneven shape can be arranged more densely in one pixel, so that application to a high definition panel having a small pixel pitch becomes easy.

  In the image display device according to the present invention, it is preferable that the lens is a lenticular lens or a fly-eye lens. Further, the display device may be a liquid crystal display device.

  A portable terminal device according to the present invention includes the above-described image display device. The portable terminal device may be a portable telephone, a portable terminal, a PDA (Personal Digital Assistance: portable information terminal), a game machine, a digital camera, or a digital video.

  According to the present invention, since the light condensed by the lens has a certain area on the surface of the reflecting plate, the light is reflected at a plurality of types of inclination angles such as an uneven slope and a flat portion, and the reflected light Travels at various angles. Since this part also advances toward the observer, it can contribute to display. Accordingly, it is possible to prevent a decrease in luminance due to the uneven shape, and it is possible to obtain an image display device having excellent display quality without a decrease in brightness in reflective display.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

(1st Embodiment)
FIG. 1 is a sectional view of a stereoscopic image display device according to a first embodiment of the present invention, and FIG. 2 is a perspective view showing a portable terminal device according to the present embodiment. The stereoscopic image display device 1 includes a reflective liquid crystal display panel 2 and a lenticular lens 3. The reflective liquid crystal display panel 2 has a configuration in which a liquid crystal layer 5 is sandwiched between a substrate 6 and a transparent substrate 7, and a pixel electrode (reflective plate 4) is formed on the surface of the substrate 6 on the liquid crystal layer side. A counter electrode (not shown) is formed on the surface of the transparent substrate 7 on the liquid crystal layer side. The pixel electrode and the counter electrode are linear electrodes extending in a direction orthogonal to each other. A pixel at a position where the pixel electrode and the counter electrode intersect is selected, and a voltage is applied between them to align the liquid crystal. Is controlled and an image is displayed.

  In the present embodiment, the reflection plate 4 is constituted by the pixel electrodes arranged on the back side of the liquid crystal layer 5. This reflector has an uneven shape 41. The size of the uneven shape 41 is the same as the uneven shape of the reflector of the conventional reflection type liquid crystal display device, but has a height of 2 μm and a pitch of 10 μm as an example.

  The lenticular lens 3 is disposed on the transparent substrate 7. The lenticular lens 3 has a large number of curved surfaces (cylindrical surfaces) in which the convex portions 31 appear at a constant pitch. The longitudinal direction of the cylindrical surface (the direction in which the curved center axis extends) is, in this embodiment, It is parallel to the direction in which the pixel electrode (reflector 4) extends. In addition, one cylindrical surface is arranged for two pixels (pixel electrodes 4).

  In the present embodiment, as described above, one display unit is composed of one left-eye pixel 4a and one right-eye pixel 4b, and each pixel emits light from the left-eye pixel in each display unit. The light thus emitted and the light emitted from the pixel for the right eye are distributed to the left eye and the right eye by one corresponding cylindrical lens of the lenticular lens 3. In this case, the external light passes through the lenticular lens 3, the transparent substrate 7 and the liquid crystal layer 5, is reflected by the reflection plate 4 located on the lower surface of the liquid crystal layer 5, and is again irradiated with the liquid crystal layer 5, the transparent substrate 7 and the lenticular. The light passes through the lens 3. At this time, external light incident on the reflector 4 from a specific direction is diffused and reflected in various directions by the uneven shape 41 on the surface of the reflector 4, and is also reflected toward the observer. Thus, reflection of the light source pattern can be prevented, and external light having various angles can be used for display.

  Thus, in the present embodiment, the distance HR between the center of the convex portion 31 on the surface of the lenticular lens 3 and the surface of the reflecting plate 4, that is, the pixel, is calculated by the above-described conventional optical system. The distance is set to be larger than the distance H between the pixel and the center of the convex portion on the surface of the lenticular lens 3 in the model. As a result, the distance HR between the lens surface and the pixel is larger than the focal length f of the lenticular lens 3. That is, in the present embodiment, the focal length f of the lenticular lens 3 is calculated by the above equations (10) to (12) and (16). At this time, the observation distance OD is, for example, an optimum observation distance defined as follows. This optimal observation distance is that light emitted from a pixel displaying the image for the right eye is incident on the right eye by locating the midpoint between the right eye and the left eye of the observer, and is incident on the left eye. The longest line among the line segments extending in the direction connecting the left-eye pixel 4a and the right-eye pixel 4b within one display unit in the three-dimensional visible range where light emitted from the pixel for displaying the image for the left eye enters. And the distance between the reflective liquid crystal display panel 2 and the minute.

  The stereoscopic image display device 1 is used, for example, for displaying an image of a mobile phone 9 as shown in FIG.

  Next, the result of a computer simulation performed to explain the effect of the present invention will be described. FIG. 3 shows an optical model used for computer simulation. In the conventional optical model of FIG. 31, the distance HR between the lens surface (center of the convex portion) and the pixel is set to 1.57 mm, which is equal to the focal length f of the lens = 1.57 mm. On the other hand, in the optical model of the present invention shown in FIG. 3, the distance HR between the surface of the lens (center of the convex portion) and the pixel is set to 1.77 mm, and the focal point f of the lens is larger than 1.57 mm. This is different from the case of FIG.

  FIG. 4A is a graph showing a simulation result when the optical model of FIG. 3 is used, and is a result when the present invention is applied. On the other hand, as a comparative example, a simulation result when the conventional optical model of FIG. 31 is used is shown in FIG. According to these figures, it can be seen that the decrease in luminance near -30 mm, which has occurred in FIG. 4B, is greatly alleviated in FIG. 4A. Therefore, the display does not darken even when observed near -30 mm.

  FIGS. 5A and 5B are conceptual diagrams for qualitatively explaining the principle of the present invention. Among them, FIG. 5A is a conceptual diagram showing a trajectory of a light ray 91 of a certain parallel light component among incident external light in the optical model shown in FIG. Since the distance H between the lens surface and the pixel is arranged so as to be equal to the focal length f, the light 91 condensed by the lenticular lens 3 is focused on the surface of the reflection plate 4 and has an uneven shape. When reflected by the slope, the light travels in a direction different from the direction of the observer. Therefore, it does not substantially contribute to display. On the other hand, in the optical model of the present invention shown in FIG. 5B, since the distance HR between the lens surface and the pixel is set to be larger than the focal length f, the light collected by the lenticular lens 3 is It has a certain area on the reflection plate 4. As a result, the light is reflected at a plurality of types of inclination angles, such as an uneven slope and a flat portion, so that the reflected light travels at various angles. Since this part also advances toward the observer, it can contribute to display. Therefore, according to the present invention, a decrease in luminance can be prevented.

  Regarding the distance HR between the lens surface and the pixel, as shown in FIG. 6, it is particularly preferable that the light condensed by the lenticular lens 3 irradiates an inclined surface having a plurality of inclination angles. As a result, the angle distribution of the reflected light can be made wider and the ratio of reflection in the viewer direction can be increased. Assuming that the pitch of the concavo-convex shape is V, a triangle having a lens pitch L as a base and a focal length f as a height, a base V with a pitch of the concavo-convex shape, and a height of a distance between the lens surface and the pixel A similar relationship holds between a triangle obtained by subtracting the focal length f from HR. Accordingly, the condition for irradiating the light condensed by the lens on the inclined surface having a plurality of inclination angles is expressed by the following equation (24). By transforming this, the following equation 25 is obtained.

  That is, it is preferable to set the distance HR between the lens surface and the pixel so as to satisfy Expression 25. In addition, when the positions of the uneven shapes are random, the present invention can be applied by setting the minimum pitch among the uneven shapes to V.

  In the display element of the present invention, it is sufficient that the pixel electrode has a reflector having an uneven shape. In the embodiment of the present invention, the case where the reflective liquid crystal display element is used has been described. However, the present invention is not limited to this. For example, a display element using an electrophoretic phenomenon can be used. In addition, the uneven shape can be applied as long as it has a structure having a slope, and is not affected by the overall shape such as a dot shape, a bar shape, and a dent shape. The driving method of the pixel electrode may be an active matrix method such as a TFT method or a TFD method, or a passive matrix method such as an STN method.

  Although the above description has been made with reference to the case of a lenticular lens, it is needless to say that the present invention can be applied to a fly-eye lens. FIG. 7 is a perspective view showing the fly-eye lens 10. As shown in FIG. 22, the lenticular lens 3 has a shape in which cylindrical lenses 3 extending in one direction are arranged in parallel with each other, and extends in a direction connecting the left-eye pixel and the right-eye pixel in one display unit. That is, the convex surface is repeated in the left-right direction, and the surface does not change in the longitudinal direction of the lenticular lens 3 orthogonal to the left-right direction. That is, the shape of the cross section extending in the left-right direction does not change in the longitudinal direction of the lenticular lens 3. On the other hand, the convex surface of the fly-eye lens 10 is repeated in both the direction connecting the left-eye pixel and the right-eye pixel and the direction orthogonal to this direction. That is, in the direction (left-right direction) where the left-eye pixel and the right-eye pixel face each other in one display unit, one convex surface is arranged for this set of left-eye and right-eye pixels. This is the same as the case of the lenticular lens, but the fly-eye lens is also provided in the direction orthogonal to the left-right direction for every two pixels (two pixels for the right eye or two pixels for the left eye). Number of convex surfaces are arranged.

  In the case of a fly-eye lens, a three-dimensional image display device is set up, and when observing the image, a dedicated image is displayed on the left and right eyes to enable stereoscopic viewing. It is also possible to distribute the image also in the direction to widen the viewing angle, or to allow the observer to see the upper and lower sides of the image. As described above, even when the fly-eye lens 10 is used as the lens, the focal length f of the lens is equal to the distance H between the surface of the reflector and the center of the convex portion of the surface of the lens, as in the above embodiment. By making them different, the same effect as in the above embodiment can be obtained.

  Further, the above description is about the case where the convex portion of the lens is arranged so as to be on the viewer side. However, even when the convex portion of the lens is arranged so as to be on the display device side. The same effect can be obtained.

  The three-dimensional image display device according to the present embodiment can be suitably applied to a mobile device such as a mobile phone, and can display a good three-dimensional image. If the stereoscopic image display device according to the present embodiment is applied to a portable device, unlike a case where the stereoscopic image display device is applied to a large-sized display device, the observer can arbitrarily adjust the positional relationship between his or her own eyes and the display screen. A quick visible range can be found quickly.

  Further, the stereoscopic image display device according to the present embodiment can be applied not only to a mobile phone but also to a mobile terminal device such as a mobile terminal, a PDA, a game machine, a digital camera, and a digital video camera.

(Second embodiment)
FIG. 8 is a sectional view of a stereoscopic image display device according to the second embodiment of the present invention. This embodiment is different from the first embodiment in that the distance HR between the lens surface and the pixel is calculated from the distance HR between the lens surface and the pixel in the conventional optical model calculated by the formulas 10 to 12. Is also set smaller. As a result, the distance HR between the lens surface and the pixel is smaller than the focal length f of the lenticular lens.

  Regarding the distance HR between the lens surface and the pixel in the present embodiment, as shown in FIG. 9, it is particularly preferable that the light condensed by the lens irradiates a slope having a plurality of inclination angles. As a result, the angle distribution of the reflected light can be made wider and the ratio of reflection in the viewer direction can be increased. This condition is expressed by the following equation 26 using the distance HR between the lens surface and the pixel, the focal length f, and the lens pitch L from the geometrical relationship, where V is the pitch of the concavo-convex shape. By transforming this, the following equation 27 is obtained.

  That is, it is preferable to set the distance HR between the lens surface and the pixel so as to satisfy Expression 27. In addition, when the positions of the uneven shapes are random, the present invention can be applied by setting the minimum pitch among the uneven shapes to V.

  According to the present invention, the distance between the lens surface and the pixel can be reduced as compared with the first embodiment of the present invention. Therefore, since the total thickness of the stereoscopic image display device can be reduced, it can be suitably used for a mobile terminal such as a mobile phone.

(Third embodiment)
FIG. 10 is a sectional view of a stereoscopic image display device according to the third embodiment of the present invention. Compared to the first embodiment of the present invention, the focal length fR of the lenticular lens in the present embodiment is set to be smaller than the focal length f in the conventional optical model calculated by Expressions 10 to 12 and 16. In this case, the distance H between the lens surface and the pixel is a value calculated by the above equations (10) to (12).

  Regarding the focal length f in the present invention, as shown in FIG. 11, it is particularly preferable that the light condensed by the lens irradiates a slope having a plurality of inclination angles. As a result, the angle distribution of the reflected light can be made wider and the ratio of reflection in the viewer direction can be increased. This condition is represented by the following equation 28 using the distance H between the lens surface and the pixel, the focal length fR, and the lens pitch L from the geometrical relationship, where V is the pitch of the concavo-convex shape. By transforming this, the following equation 29 is obtained.

  That is, it is preferable to set the focal length fR of the lenticular lens so as to satisfy Expression 29. In addition, when the positions of the uneven shapes are random, the present invention can be applied by setting the minimum pitch among the uneven shapes to V.

  The present embodiment has an advantage that it can be applied to the case where the distance between the lens surface and the pixel is fixed as compared with the first embodiment. That is, in the first embodiment, since the distance H between the lens surface and the pixel is changed from a value satisfying Expressions 1 to 9, it is necessary to redesign other parameters such as the observation distance OD. If the redesign is not performed, the three-dimensional image display device will not be in the ideal design state, and adverse effects such as a shift in the three-dimensional visible region between the center and the end of the display screen will occur. In the present embodiment, such a problem does not occur because only the focal length f needs to be changed.

(Fourth embodiment)
FIG. 12 is a sectional view of a stereoscopic image display device according to the fourth embodiment of the present invention. The present embodiment is different from the third embodiment in that the focal length fR of the lenticular lens is set to be larger than the focal length f calculated by the formulas (10) to (12) and (16). H is a point that is a calculated value in the conventional optical model calculated by Expressions 10 to 12.

  Regarding the focal length f, as shown in FIG. 13, it is particularly preferable that the light condensed by the lens irradiates a slope having a plurality of inclination angles. As a result, the angle distribution of the reflected light can be made wider and the ratio of reflection in the viewer direction can be increased. This condition is expressed by the following equation 30 using the distance H between the lens surface and the pixel, the focal length fR, and the lens pitch L from the geometrical relationship, where V is the pitch of the uneven shape. When this is modified, the following Expression 31 is obtained.

  That is, it is preferable to set the focal length fR of the lenticular lens so as to satisfy Expression 31. In addition, when the positions of the uneven shapes are random, the present invention can be applied by setting the minimum pitch among the uneven shapes to V.

  According to the present embodiment, there is an advantage that the focal length fR can be set larger than in the third embodiment of the present invention. As a result, the height of the unevenness of the lens can be reduced, so that the lens pattern becomes less noticeable, and the display quality of the stereoscopic image is improved.

(Fifth embodiment)
FIG. 14 is a sectional view of a stereoscopic image display device according to a fifth embodiment of the present invention. The present embodiment is different from the first to fourth embodiments in that the focal length f and the distance H between the lens surface and the pixel use the values calculated by the above equations 10 to 12 and 16, and the concavo-convex shape Is set to 50 ° or more.

  In order to study this embodiment in detail, computer simulation was performed while changing the inclination angle θ of the uneven shape between 25 ° and 75 °. FIG. 15 shows a simulation result. 15A is θ = 75 °, FIG. 15B is θ = 65 °, FIG. 15C is θ = 60 °, FIG. 15D is θ = 50 °, and FIG. FIG. 15F shows the result when θ = 35 °, and FIG. 15F shows the result when θ = 25 °. When the inclination angle θ is smaller than 50 °, the luminance is reduced around −30 mm, but is significantly reduced when the inclination angle θ is 50 ° or more. That is, the display does not become dark even when observed near -30 mm.

  FIG. 16 is a conceptual diagram for qualitatively explaining the principle of the embodiment of the present invention. Among them, FIG. 16A is a conceptual diagram showing a trajectory of a ray of a parallel light component of incident light in the conventional optical model shown in FIG. The distance H between the lens surface and the pixel is arranged to be equal to the focal length f, and the inclination angle of the uneven shape is a value smaller than 50 °, for example, 30 °. In this case, the light condensed by the lens travels in a direction different from the direction of the observer when reflected by the uneven slope. Therefore, it does not substantially contribute to display. On the other hand, in the optical model of the present embodiment shown in FIG. 15B, the inclination angle of the uneven shape is set to a value of 50 ° or more, for example, 60 °. As a result, a part of the light reflected on one slope of the concavo-convex shape travels toward the observer after being reflected again on another slope. Therefore, it is possible to prevent a decrease in luminance due to the uneven shape.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described. FIG. 17 is a perspective view showing a stereoscopic image display device according to a sixth embodiment of the present invention, and FIGS. 18A and 18B are cross-sectional views for qualitatively explaining the principle of the present embodiment. 17A is a cross-sectional view taken along line AA shown in FIG. 17, and FIG. 17B is a cross-sectional view taken along line BB shown in FIG. The stereoscopic image display device according to the present embodiment is different from the above-described first to fifth embodiments in that an inclined surface having a concave / convex shape 41 with a certain inclination angle in the arrangement direction of the cylindrical lenses 3 a constituting the lenticular lens 3. Is that the existence probabilities of are substantially uniform in one pixel. The focal length f of the lenticular lens 3 is equal to the distance H between the lens surface of the lenticular lens 3 and the pixel, and the inclination angle of the uneven shape 41 is, for example, 30 °.

  At the cross-sectional positions shown in FIGS. 18A and 18B, there are two types of positive and negative tilt angles in which the absolute values of the tilt angles of the uneven shape 41 are equal to each other. The positions of the concavities and convexities in the arrangement direction of the cylindrical lenses 3a are shifted from each other by half a pitch of the concavo-convex shape 41, that is, a half cycle. That is, in the arrangement direction of the cylindrical lenses 3a, the phase of the uneven shape 41 in the region shown in FIG. 18A and the phase of the uneven shape 41 in the region shown in FIG. I have.

  Since the cylindrical lens 3a does not have a lens function in the longitudinal direction, the optical effect of the uneven shape 41 is obtained by integrating the effect in the longitudinal direction of the cylindrical lens 3a. Therefore, in the three-dimensional image display device shown in FIG. 17 and FIGS. 18A and 18B, the optical effect of the uneven shape 41 is the same as the effect of the uneven shape 41 shown in FIG. The effect of the uneven shape 41 shown in b) is superimposed. As a result, in one pixel, at any position in the arrangement direction of the cylindrical lenses 3a, positive and negative inclination angles always exist at any positions in the longitudinal direction of the cylindrical lens 3a. Therefore, the optical characteristics of the stereoscopic image display device according to the present embodiment are equivalent to the case where the same inclination angle is continuously arranged at all positions in the arrangement direction of the cylindrical lenses 3a.

  Further, in FIG. 17, the number of irregularities is four, and each of the two irregularities is arranged as a set and shifted by a half cycle, so that the inclined surface having the above-mentioned inclination angle exists at an arbitrary position in the arrangement direction of the cylindrical lenses 3a. The probabilities are kept constant. As a result, it is possible to more reliably prevent the brightness from being reduced due to the uneven shape.

  Further, it is preferable that the concave and convex shapes 41 are arranged so as to be shifted in the arrangement direction of the cylindrical lenses 3a so as to be dense in the longitudinal direction of the cylindrical lenses 3a. For example, when the concavo-convex shape 41 is a conical shape, a plurality of cones are arranged in one row in the arrangement direction of the cylindrical lenses 3a, and between adjacent cones in this arrangement direction, the cones of the adjacent row enter. It may be arranged. By doing so, the pitch of the irregularities 41 in the longitudinal direction of the cylindrical lens 3a can be made smaller than the pitch of the irregularities 41 in the arrangement direction of the cylindrical lenses 3a. As a result, in the longitudinal direction of the cylindrical lens 3a, the number of irregularities 41 arranged in one pixel increases, and the reflected light can be made more uniform by the above-described integration effect. For this reason, it becomes much easier to apply the stereoscopic image display device according to the present embodiment to a high definition panel having a small pixel pitch.

  The focal length f of the lenticular lens 3 may be different from the distance H between the lens surface of the lenticular lens 3 and the pixel, and the inclination angle of the uneven shape 41 may be, for example, 50 ° or more. Further, the stereoscopic image display device according to the present embodiment may be a transflective device in which a reflection area and a transmission area are provided in each pixel.

(Seventh embodiment)
FIG. 19 is a perspective view of a stereoscopic image display device according to the seventh embodiment of the present invention. The display panel 200 of the stereoscopic image display device 1 according to the present embodiment is a transflective display element in which pixel electrodes have a transmissive region and a reflective region. Specifically, the left-eye pixel is composed of a left-eye pixel (transmission region) 511 and a left-eye pixel (reflection region) 512, and similarly, the right-eye pixel is a right-eye pixel (transmission region). 521) and a right-eye pixel (reflection region) 522. The pixel electrodes of the left-eye pixel (reflection region) 512 and the right-eye pixel (reflection region) 522 are reflection plates formed of a non-transparent layer such as a metal electrode. The uneven shape is provided as described above. The relationship between the concave and convex shape of the reflector and the lenticular lens 3 is the same as in the above-described first to fifth embodiments of the present invention. The pixel electrodes of the left-eye pixel (transmission region) 511 and the right-eye pixel (transmission region) 521 are formed of a transparent electrode such as ITO (indium-tin-oxide). A backlight light source (not shown) for a transmission area is provided below these display panels.

  In the three-dimensional image display device of the present embodiment configured as described above, the transmission region transmits light from the backlight light source, and the reflection region can reflect external light such as natural light and indoor illumination light. Transmissive display and reflective display can be realized. As a result, a clear display can be performed regardless of the degree of surrounding brightness.

  In the present embodiment, a transflective display element has been described, but the present invention is similarly applicable to a slightly transmissive display element, a slightly reflective display element, and the like.

(Eighth embodiment)
Next, an eighth embodiment of the present invention will be described. FIG. 20 is a perspective view illustrating the portable terminal device according to the present embodiment, and FIG. 21 is an optical model diagram illustrating an operation of the image display device according to the present embodiment. As shown in FIG. 20, in the present embodiment, an image display device is incorporated in a mobile phone 9 as a mobile terminal device. In the present embodiment, the longitudinal direction 11 of the cylindrical lens 3a constituting the lenticular lens 3 is the horizontal direction of the image display device, ie, the horizontal direction of the image, as compared with the first embodiment. The difference is that the arrangement direction 12 of the lenses 3a is the vertical direction, that is, the vertical direction of the image. Although only four cylindrical lenses 3a are shown in FIG. 20 for simplicity of illustration, actually, the number of cylindrical lenses 3a is equal to the number of pixels arranged in the longitudinal direction 11.

  As shown in FIG. 21, the display panel 2 includes a plurality of pixel pairs each including a first viewpoint pixel 53 and a second viewpoint pixel 54 arranged in a matrix. The arrangement direction of the first viewpoint pixel 53 and the second viewpoint pixel 54 in one pixel pair is the arrangement direction 12 of the cylindrical lens 3a, that is, the vertical direction (vertical direction) of the screen. The configuration of the present embodiment other than the above is the same as that of the above-described first embodiment.

  Next, the operation of the image display device according to the present embodiment will be described. As shown in FIG. 21, the first viewpoint pixel 53 of the reflective display panel 2 displays an image for the first viewpoint, and the second viewpoint pixel 54 displays an image for the second viewpoint. The image for the first viewpoint and the image for the second viewpoint are not stereoscopic images having parallax but are plane images. Further, the two images may be mutually independent images, or may be images showing mutually related information.

  Then, external light such as natural light and illumination light passes through the lenticular lens 3 from the front and enters the liquid crystal display panel 2, is reflected by the pixels 53 and 54, and travels toward the lenticular lens 3. The light reflected by the first viewpoint pixel 53 and the second viewpoint pixel 54 is refracted by the cylindrical lens 3a, and is emitted toward the regions E1 and E2, respectively. At this time, when the observer positions both eyes in the region E1, the image for the first viewpoint can be observed. When the observer positions both eyes in the region E2, the image for the second viewpoint can be observed. Images can be observed.

  In the present embodiment, the observer simply changes the angle of the mobile phone 9 to position his or her own eyes in the region E1 or the region E2, and selects an image for the first viewpoint or an image for the second viewpoint. It has the advantage of being observable. In particular, when there is a relationship between the image for the first viewpoint and the image for the second viewpoint, the respective images can be switched and observed alternately by a simple method of changing the observation angle. Is greatly improved. In addition, when the image for the first viewpoint and the image for the second viewpoint are arranged in the horizontal direction, different images may be observed by the right eye and the left eye depending on the observation position. In this case, the observer is confused and cannot recognize the image of each viewpoint. On the other hand, as shown in the present embodiment, when the images for multiple viewpoints are arranged in the vertical direction, the observer can always observe the images for each viewpoint with both eyes. Can be recognized. The other effects of the present embodiment are the same as those of the above-described first embodiment. This embodiment can be combined with any one of the above-described second to sixth embodiments.

  In the above-described first to eighth embodiments, a stereoscopic image is displayed by supplying an image having a parallax to the left and right eyes of one observer and being mounted on a mobile phone or the like. Although an example of an image display device that simultaneously supplies a plurality of types of images to a human observer has been described, the image display device according to the present invention is not limited to this, and includes a large display panel, and is provided to a plurality of observers. May be supplied with a plurality of different images.

FIG. 1 is a cross-sectional view illustrating a stereoscopic image display device according to a first embodiment of the present invention. FIG. 1 is a perspective view showing a portable terminal device according to a first embodiment of the present invention. FIG. 3 is an optical model diagram for performing computer simulation in the first embodiment of the present invention. FIG. 4 is a graph showing a result of a computer simulation in the first embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating the principle of the first embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a state where light condensed by a lens irradiates a plurality of slopes in the first embodiment of the present invention. It is a perspective view showing a fly-eye lens used instead of a lenticular lens. It is a sectional view showing a second embodiment of the present invention. FIG. 9 is a cross-sectional view illustrating a state where light condensed by a lens irradiates a plurality of slopes in a second embodiment of the present invention. It is a sectional view showing a third embodiment of the present invention. FIG. 13 is a cross-sectional view illustrating a state in which light condensed by a lens irradiates a plurality of slopes in a third embodiment of the present invention. It is a sectional view showing a fourth embodiment of the present invention. FIG. 13 is a cross-sectional view illustrating a state in which light condensed by a lens irradiates a plurality of slopes in a fourth embodiment of the present invention. It is a sectional view showing a fifth embodiment of the present invention. FIG. 16 is a graph showing the results of computer simulation in the fifth embodiment of the present invention. It is a conceptual diagram for showing the principle of a 5th embodiment of the present invention. FIG. 15 is a perspective view illustrating a stereoscopic image display device according to a sixth embodiment of the present invention. (A) and (b) are sectional views for qualitatively explaining the principle of the present embodiment, (a) is a sectional view taken along line AA shown in FIG. 17, and (b) is a sectional view. FIG. 18 is a sectional view taken along line BB shown in FIG. It is a typical perspective view showing a 7th embodiment of the present invention. It is a perspective view showing the personal digital assistant concerning an 8th embodiment of the present invention. FIG. 4 is an optical model diagram illustrating an operation of the image display device according to the embodiment. FIG. 3 is a perspective view illustrating a shape of a lenticular lens 3. FIG. 4 is an optical model diagram showing a stereoscopic image display method using a conventional lenticular lens. FIG. 4 is an optical model diagram showing a stereoscopic image display method using a conventional parallax barrier. It is a conceptual diagram for showing the conventional reflecting plate which has a concavo-convex shape. FIG. 10 is a perspective view showing a conventional stereoscopic image display device using a lenticular lens and a display element. It is sectional drawing in the stereoscopic image display apparatus using the conventional lenticular lens and the display element. FIG. 9 is a model diagram showing the size of each part in a conventional stereoscopic image display device using a lenticular lens and a display element. FIG. 4 is an optical model diagram for performing computer simulation in a conventional stereoscopic image display device using a lenticular lens and a display element. FIG. 9 is a graph showing a result of computer simulation in a stereoscopic image display device using a conventional lenticular lens and a display element. FIG. 9 is an optical model diagram for performing computer simulation when a reflector having a concave-convex shape is applied to a stereoscopic image display device using a conventional lenticular lens and a display element. FIG. 9 is a graph showing a result of a computer simulation when a reflector having an uneven shape is applied to a stereoscopic image display device using a conventional lenticular lens and a display element.

Explanation of reference numerals

Reference Signs List 1: 1-dimensional image display device 2: reflective liquid crystal display panel 200: semi-transmissive liquid crystal display panel 3, 121; lenticular lens 3a; cylindrical lens 31, 122: convex portion 4: reflective plate 41: concave and convex shape 4a: left eye Pixel 4b: Right-eye pixel 5: Liquid crystal layer 6: Substrate 7: Transparent substrate 8: Observation position 9; Mobile phone 91: Light ray 10: Fly-eye lens 11; Longitudinal direction of cylindrical lens 12; Arrangement direction of cylindrical lens 17; Light-emitting area 18; Light-receiving surface 19; Light source 31; Convex part 41; Concavo-convex shape 42; Light-shielding part 51; Left-eye pixel 52; Right-eye pixel 53; First viewpoint pixel 54; Second viewpoint pixel 61, 142 Left eye 62, 141; right eye 105; parallax barrier 105a; slit 106: display panel 107; three-dimensional visible range 107a; 107 b; optimum viewing plane 108: light source 123: pixel 143; right eye 141 and left eye 142 and the midpoint 181 and 182; the light beam 511: left-eye pixel (transmission region)
512: Left eye pixel (reflection area)
521: Right eye pixel (transmission area)
522: Right eye pixel (reflection area)

Claims (23)

A display panel in which a plurality of display units each including at least a pixel for displaying an image for a first viewpoint and a pixel for displaying an image for a second viewpoint in one display unit are arranged in a matrix; A lens provided with a plurality of lens elements arranged to refract light emitted from each of the pixels and emit light in different directions; and a lens disposed in the display panel or behind the display panel to emit external light. And a reflector having an uneven shape on the surface, wherein the focal length f of the lens is different from the distance H between the surface of the reflector and the vertex of the lens. Image display device. A plurality of display units each including at least a pixel having a transmissive region and a reflective region in one display unit and displaying an image for a first viewpoint and a pixel having a transmissive region and a reflective region and displaying an image for a second viewpoint are formed in a matrix. A lens provided with a plurality of lens elements disposed in front of the display panel and refracting light emitted from the pixels and emitting light in different directions from each other; and A light source that irradiates the transmission area with light, and a reflection plate that is disposed behind the reflection area in the display panel or the reflection area of the display panel, reflects external light toward the lens, and has an uneven shape on the surface. Wherein the focal length f of the lens is different from the distance H between the surface of the reflector and the vertex of the lens. The image display device according to claim 1, wherein a focal length f of the lens is smaller than a distance H between a surface of the reflector and a vertex of the lens. The pitch of the convex portions on the surface of the lens in a first direction from the pixel displaying the image for the first viewpoint to the pixel displaying the image for the second viewpoint is L, and the pitch in the first direction is When the minimum pitch of the concave and convex shape of the reflector is V, the focal length f of the lens and the distance H between the surface of the reflector and the vertex of the lens satisfy the following expression. The image display device as described in the above.

When the optimal observation distance is OD, the pixel expansion projection width at the distance OD is e, the refractive index of the lens is n, and the pixel pitch of the display element is P, the focal length f of the lens satisfies the following equation. The image display device according to claim 4, wherein:

The optimum viewing distance OD, the pixel expansion projection width e, the refractive index n of the lens, the distance H between the surface of the reflector and the center of the convex portion of the lens surface, and the pixel pitch P of the display element are represented by the following equations. The image display device according to claim 4, wherein the following condition is satisfied.

3. The image display device according to claim 1, wherein a focal length f of the lens is larger than a distance H between a surface of the reflection plate and a vertex of the lens. 4. The pitch of the convex portions on the surface of the lens in a first direction from the pixel displaying the image for the first viewpoint to the pixel displaying the image for the second viewpoint is L, and the pitch in the first direction is When the minimum pitch of the concave and convex shape of the reflector is V, the focal length f of the lens and the distance H between the surface of the reflector and the vertex of the lens satisfy the following formula. The image display device as described in the above.

The said optimal observation distance OD, the said pixel expansion projection width e, the refractive index n of the said lens, the focal length f of the said lens, and the pixel pitch P of a display element satisfy | fill the following numerical formula. Image display device.

The optimal observation distance OD, the pixel expansion projection width e, the refractive index n of the lens, the distance H between the surface of the reflector and the vertex of the lens, and the pixel pitch P of the display element satisfy the following formula. The image display device according to claim 8, wherein:

A display panel in which a plurality of display units each including at least a pixel for displaying an image for a first viewpoint and a pixel for displaying an image for a second viewpoint in one display unit are arranged in a matrix; A lens provided with a plurality of lens elements arranged to refract light emitted from each of the pixels and emit light in different directions; and a lens disposed in the display panel or behind the display panel to emit external light. An image display device, comprising: a reflecting plate that reflects light toward the surface and has an uneven shape on the surface; and the uneven shape on the surface of the reflecting plate has a shape that reflects incident light a plurality of times. . A plurality of display units including a pixel having a transmission area and a reflection area in one display unit and displaying an image for a first viewpoint and a pixel having a transmission area and a reflection area and displaying an image for a second viewpoint are arranged in a matrix. A display panel disposed, a lens in which a plurality of lens elements disposed in front of the display panel and refracting light emitted from the pixels and emitting light in different directions from each other are formed; and A light source that irradiates light to a transmission region, a reflection plate that is disposed behind the reflection region in the display panel or the reflection region of the display panel, reflects external light toward the lens, and has an uneven shape on the surface, An image display device, comprising: a concave and convex shape on the surface of the reflection plate having a shape that reflects incident light a plurality of times. The image display device according to claim 11, wherein an inclination angle of the concave-convex shape is 50 ° or more. 14. The image display device according to claim 1, wherein the lens is a lenticular lens or a fly-eye lens. A display panel in which a plurality of display units each including at least a pixel for displaying an image for a first viewpoint and a pixel for displaying an image for a second viewpoint in one display unit are arranged in a matrix; A lenticular lens in which a plurality of cylindrical lenses that are arranged to refract light emitted from each of the pixels and emit light in mutually different directions is formed, and that external light is arranged in the display panel or behind the display panel. A reflecting plate that reflects toward the lens and has an uneven shape on the surface, and in the arrangement direction of the cylindrical lenses, the existence probability of a slope having a certain inclination angle in the uneven shape is uniform in the pixel. An image display device comprising: A plurality of display units including a pixel having a transmission area and a reflection area in one display unit and displaying an image for a first viewpoint and a pixel having a transmission area and a reflection area and displaying an image for a second viewpoint are arranged in a matrix. A lenticular lens in which a plurality of cylindrical lenses that are disposed in front of the display panel, are disposed in front of the display panel, and refract light emitted from the pixels and emit light in different directions from each other; A light source that irradiates the transmission area with light, and a reflection plate that is disposed behind the reflection area in the display panel or the reflection area of the display panel, reflects external light toward the lens, and has an uneven shape on the surface. In the arrangement direction of the cylindrical lenses, the existence probability of a slope having a certain inclination angle in the uneven shape is uniform in the pixel. An image display device, characterized in that. In the arrangement direction of the cylindrical lenses, the phase of the uneven shape formed in one region of each pixel and the phase of the uneven shape formed in another region of the pixel are mutually shifted. 17. The image display device according to claim 15, wherein: 18. The image display device according to claim 17, wherein the phase shift is half the pitch of the uneven shape. The image display device according to any one of claims 15 to 18, wherein a pitch of the concave-convex shape in a longitudinal direction of the cylindrical lens is smaller than a pitch of the concave-convex shape in an arrangement direction of the cylindrical lens. The image for the first viewpoint is a left-eye image, the image for the second viewpoint is a right-eye image having parallax with respect to the left-eye image, and displays a stereoscopic image. The image display device according to claim 1, wherein: The image display device according to any one of claims 1 to 20, wherein the display device is a liquid crystal display device. A mobile terminal device comprising the image display device according to claim 1. The mobile terminal device according to claim 22, wherein the mobile terminal device is a mobile phone, a mobile terminal, a PDA, a game machine, a digital camera, or a digital video.

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